#define _CRT_SECURE_NO_WARNINGS 1
#include<stdio.h>
#include<math.h>
int main()
{
	float a, b, x;
	printf("please enter a,b:");
	scanf("%f%f", &a, &b);
	x = (b + sqrt(b * b + 2 * a)) / (a - b);
	printf("X=%.2f", x);
	return 0;
}
